Roller supporting means for duplicators



Jan. 28, 1969 E. v. BYERS 3,424,083

ROLLER SUPPORTING MEANS FOR DUPLICATORS Filed June 15, 1965 4 Edward 144 20) yezu' ATTORNEY-5:

United States Patent 3,424,083 ROLLER SUPPORTING MEANS FOR DUPLICATORS Edward Victor Byers, Nottingham, England, assignor to Zephon Limited, Nottingham, England Filed June 15, 1965, Ser. No. 464,001 US. Cl. 101132 11 Claims Int. Cl. B41f 11/08; 133% 3/04 ABSTRACT OF THE DISCLOSURE This invention relates to improvements in duplicators of the kind in which the matter to be duplicated is produced in a special ink on the back of a sheet of paper to produce a master copy and this inked surface is placed in contact with the surface of a sheet of paper, the surface of the paper having been treated with a solvent for the ink and the two sheets then pressed into close contact, usually by passing them together between a pair of rollers, so that a facsimile of the original is obtained on the sheet treated with the solvent. The solvent is solid at normal temperature and the density of the facsimilies obtained from the master copy depends upon the pressure applied, the duration of the pressure and the state of the master copy. In an alternative method the copy paper is moistened with a spirit solvent before being placed in contact with the master copy and the pressure applied by passing the sheets between rollers. To obtain satisfactory copies a fairly high pressure is required between the rollers and has to be evenly distributed across the rollers. For this reason, in machines as hitherto constructed the rollers and their bearings have been made robust in order to prevent any bending of the rollers due to the pressure they exert on each other and have to be made to a high standard of accuracy with the resulting increase in the cost of production. Furthermore provision has to be made to disengage the rollers from each other when the machine is not in use to prevent one roller from marking the other if left standing for any length of time in contact with each other. The object of the present invention is to provide a roller duplicating machine in which even distribution of the pressure is obtained across the rollers Without the need for robust construction or the provision of a high degree of accuracy or the provision of means to separate the rollers when the machine is not in use and consequently considerably reduce the cost of production.

According to this invention a roller duplicating machine comprises a smooth surfaced roller, preferably rubber or plastic covered, rotatably mounted in bearings in a frame and a second roller of smaller diameter dis- 3,424,083 Patented Jan. 28, 1969 posed below the other roller and having longitudinal flexibility and pressed towards the larger roller by a pluralty of spaced members which engage the underside of the smaller roller and are pressed upwards by a spring or springs. The members preferably have seats thereon to act as bearings for supporting the smaller roller. The spring or springs preferably comprises one or more strips of spring steel engaging under a part or parts of the bearing members and passing over fixed supports, located intermediate the bearing members, and adapted to bend the strip into a sinuous form so that it exerts upward pressure on the bearing members. Provision may be made to limit the upward movement of the bearing members in a position where the smaller roller is just clear of the larger roller so that pressure is only exerted by the smaller diameter roller on the other roller when a flat platen of suitable thickness is placed between them.

The invention will now be more particularly described with reference to the accompanying drawings in which:

FIGURE 1 is a front elevation, partly in section, and

FIGURE 2 is a plan showing part of a duplicator con.- structed according to this invention.

FIGURE 3 is a sectional side elevation on the line XX of FIGURE 1.

'FIGURE 4 is a fragmentary central longitudinal section taken on the line Y--Y on FIGURE 2.

Like numerals indicate like parts throughout the drawmgs.

In carrying out this invention a roller 1 of suitable diameter is carried by an axle mounted at each end in a bearing in upward extensions 2, 3 on a base 4. A trough 5 is formed in the base 4 below the roller 1. (The roller 1 is formed or moulded in any convenient manner and is preferably provided with a rubber or plastic covering having a smooth surface. Disposed in the trough 5 below the roller is a second roller 6 of smaller diameter than the other roller 1 and this roller 6 has some longitudinal. flexibility and may conveniently comprise a length of nylon rod which has the necessary amount of longitudinal flexibility. The nylon rod or roller 6 is supported by a plurality of bearing members 7 spaced along its length. The bearing surfaces of the bearing members 7 are substantially semi-cylindrical and engage with the underside of the roller 6 so that they do not obstruct the passage of sheets between the rollers 1 and 6.

The bearing members 7 are pressed upwards by a spring or by springs to press the lower roller 6 towards the upper roller 1. Preferably the spring comprises one or more spring steel strips 8, 9 which are located under the shoulders on each bearing member. Located under the bearing members 7 and engage with the underside of shoulders on each bearing member. Located under the spring steel strips are a plurality of fixed supports 10 which extend upwards from the base 11 of the trough 5 and engage with the underside of the spring steel strips 8, 9. The supports 10 are located intermediate the bearing members 7 and are of such a height that the spring steel strips are caused to follow a sinuous path and so exert upward pressure on the bearing members 7. In order to reduce friction between the nylon roller 6 and the bearing members 7, the latter are preferably made from acetal resin material sold under the registered trademark Delrin, which material has high anti-friction properties.

The bearing members 7 are retained in space relationship by means of flexible connections 12 which extend across between the bearing members and which permit upward movement of the bearing members 7 but prevent them moving laterally.

The bearing members 7 may press the nylon roller 6 into contact with the other roller 1 but are preferably prevented from this. For this purpose the upper edges of the sides of the trough may be formed with ribs which project over the bearing members 7 and limit their upward movement at a point where the nylon roller 6 is just clear of the other roller 1 so that they cannot be left in contact with each other when the machine is not in use and cause marking of one or both rollers.

In the preferred arrangement shown in the drawings, the lower ends of the bearing members are formed with lateral projections 13 on each side and these projections 13 engage with the underside of the trough and limit the upward movement of the bearing members 7. In order to place the bearing members 7 in position T shaped slots 14, see FIG. 2, are formed in the base 11 of the trough 5 so that the projections 13 can be passed through the widest part of the slots and the bearing members 7 then moved laterally for the projections to engage under the base 11 of the trough. After the bearing members 7 have been placed in position one end of the bearing member assembly is anchored to the base 4 or retained in position in any other convenient manner.

To use the duplicator the master copy is placed under a sheet of copy paper and both sheets are placed on a flat flexible platen and then passed through the rollers together with the platen. The upper roller 1 is turned for this purpose by a handle 15 secured to its axle and the thickness of the platen opens the bight between the rollers and allows the lower roller 6 to exert the necessary pressure to produce a facsimile of the master copy on the copy sheet.

The flexibility of the lower roller 6 allows it to follow any inequalities in the surface of the upper roller 1 so that even pressure is obtained across the rollers as the platen and sheets are passed between the rollers and this result is obtained without the necessity for robust construction or a high degree of accuracy in the rollers which results in a considerable saving in the cost of production of the duplicator.

The method of obtaining even contact across the rollers whilst particularly applicable to the rollers of duplicators is not limited to use with rollers for this purpose, but is also applicable where even pressure is required across between a pair of rollers without providing a high degree of accuracy in the rollers.

What I claim is:

1. A roller duplicating machine comprising a smooth surfaced roller rotatably mounted in bearings in a frame and a second roller of smaller diameter disposed below said smooth surfaced roller and having longitudinal flexibility greater than the flexibility of said smooth surfaced roller and pressed towards the larger roller by a plurality of independently movable members which engage with the underside of the smaller roller and are stationary relative to the frame except for linear movement in a direction perpendicular to the axis of the second roller and spaced intermediately of the ends of said second roller and are pressed upwards by a strip spring means engaging and common to all said spaced members, said members comprising the only support for said smaller roller.

2. A roller duplicating machine according to claim 1 in which said spaced members are formed with seats which form bearings for the smaller roller.

3. A roller duplicating machine according to claim 2 in which said spaced members are located in a trough in the base of the frame and are pressed towards the larger roller by said spring means.

4. A roller duplicating machine according to claim 3 in which said spring means passes in undulations over supports located on the base of the trough, in between the members, said supports and members cooperating to cause the strip means to have said undulated configuration of generally repetitive portions, each repetitive portion being of a length substantially equal to the distance between adjacent ones of said members.

5. A roller duplicating machine according to claim 4 in which the upward movement of the spaced members is limited to prevent the smaller roller moving into contact with the larger roller.

6. A roller duplicating machine according to claim 3 in which the spaced members are connected together by flexible connections.

7. A roller duplicating machine according to claim 6 in which the spaced members and flexible connections form an assembly providing bearings and support for the smaller roller and means are provided to hold the assembly against movement longitudinally of the trough after it has been placed in position therein.

8. A roller duplicating machine comprising a smooth surfaced roller rotatably mounted in bearings in a frame and a second roller of smaller diameter disposed below said smooth surfaced roller and having longitudinal flexibility greater than the flexibility of said smooth surfaced roller and pressed towards the larger roller by a plurality of members which engage with the underside of the smaller roller and are stationary relative to the frame except for linear movement in a direction perpendicular to the axis of the second roller and spaced intermediately of the ends of said second roller and are pressed upwards by spring means, said members being formed with seats which form bearings for the smaller roller, said members being located in a trough in the base of the frame and are pressed towards the larger roller by said spring means the upward movement of the members being limited to prevent the smaller roller moving into contact with the larger roller, and the upward movement of the spaced members being limited by ribs along the top edges of the trough engaging the tops of the members.

9. A roller duplicating machine comprising a smooth surfaced roller rotatably mounted in bearings in a frame and a second roller of smaller diameter disposed below said smooth surfaced roller and having longitudinal flexiblity greater than the flexibility of said smooth surfaced roller and pressed towards the larger roller by a plurality of members which engage with the underside of the smaller roller and are stationary relative to the frame except for linear movement in a direction perpendicular to the axis of the second roller and spaced intermediately of the ends of said second roller and are pressed upwards by spring means, said members being formed with seats which form bearings for the smaller roller, said members being located in a trough in the base of the frame and pressed towards the larger roller by said spring means, the upward movement of the members being limited to prevent the smaller roller moving into contact with the larger roller, and the lower ends of the spaced members passing through slots in the base of the trough and having thereon lateral projections which engage with the outer side of the base of the trough.

10. A roller duplicating machine according to claim 9 in which the spaced members are pressed towards the larger roller by two spring steel strips which engage under shoulders formed on the sides of the members.

11. A duplicating machine comprising a frame, a smooth surfaced first roller rotatably mounted in bearings in said frame, a second roller of smaller diameter than said first roller and being disposed beneath said first roller; said second roller having longitudinal flexibility greater than the flexibility of said smooth surfaced roller, and common means for both supporting said second roller and pressing said second roller toward said first roller; said common means comprising a plurality of parallel spaced and independently movable bearing plates in engagement against the under side of said second roller and undulated spring strip means common to all of said bearing plates for urging said bearing plates into engagement with said second roller.

3,060,847 10/1962 Rogers et a1. 101-132.5 3,246,601 4/1966 Fischer 101-350 2,851,869 9/1958 Quoos et a1. 100-160 X 3,306,195 2/1967 Cutri 101-247 X References Cited UNITED STATES PATENTS 5 ROBERT E. PULFREY, Primary Examiner.

E. S. BURR, Assistant Examiner. Ford et a1 101-132 Whittum 100-170 X CL Caspari et a]. 19-65 10 308-26; 100-160; 101-216 Gamrneter et a1. 101-247 X 

